Absent pulmonary valve

Definition

Absent pulmonary valve is a rare defect in which the pulmonary valve, through which oxygen-poor blood flows from the heart to the lungs (where it picks up oxygen) is either missing or poorly formed. This condition is present at birth (congenital).

Alternative Names

Causes, incidence, and risk factors

Absent pulmonary valve occurs when the pulmonary valve doesn't form or develop properly while the baby is in the mother's womb. It often occurs as part of a rare condition called tetralogy of Fallot.

When the pulmonary valve is missing or does not work well, not enough blood can flow to the lungs to get oxygen.

There is also usually a hole between the left and right ventricles of the heart (ventricular septal defect). This defect will also lead to low-oxygen blood being pumped out to the body.

The skin will have a blue appearance (cyanosis), because the body's blood contains a low amount of oxygen.

Absent pulmonary valve also results in very enlarged (dilated) branch pulmonary arteries (the arteries that carry blood to the lungs). They can become so enlarged that they press on the tubes that bring air to the lungs (bronchi) and cause breathing problems.

Other heart defects that can occur with absent pulmonary valve include:

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